The present invention relates to a mechanical pencil with a tubular endcap or cover to be attached to a rear end of the pencil body, wherein manual actuation of an actuation button projecting rearwardly from the cover advances the lead contained within the pencil body.
The removable cover of a known mechanical pencil has a function to protect a tip of the pencil, and a function to aid carriage in the pocket of the user if the cover is provided with a clip on the outer surface thereof. With such known pencils, however, after the cover is removed from the pencil tip and then mounted on the rear end of the pencil for writing purposes, the actuation button, which is designed to be engaged with a lead feed mechanism within the pencil body, must be actuated manually. If the lead is already placed in the tip or sleeve of the pencil such that a front end of the lead is flush with the front end of the pencil tip, the actuation button must be operated manually by, in general, pressing the button towards the pencil tip two times. The two-time operation is based upon the fact that a projection length, or increment, of the lead from the pencil tip is generally and desirably selected to be, for example, about 1.0 mm in accordance with the mechanical strength of the lead. When the lead is worn during writing with a small length, for example about 0.5 mm, of the lead still projecting from the tip, it is enough to operate the button one time so as to obtain a further increment of about 0.5 mm so that a total projecting length of the lead equals the desired length, for example about 1.0 mm. That is, the pencil is generally designed such that one operation of the actuation button can advance the lead half the desired extension length, for example about 0.5 mm. Accordingly, it is necessary to operate manually the actuation button twice when the pencil is to be used, after the endcap or cover is removed from a front portion of the pencil body and then mounted on the rear end of the pencil body.